Caracterización parcial y respuesta bajo condiciones de hiperregulación de las actividades de Na+-K+ ATPasa y fosfatasa alcalina levamisol-sensible en músculo de la quela del cangrejo eurihalino Cyrtograpsus angulatus

En el presente trabajo se estudió la presencia, características y respuesta a la salinidad ambiental de las actividades de Na+-K+ ATPasa y fosfatasa alcalina (AP) levamisol-sensible en el músculo de la quela del cangrejo eurihalino Cyrtograpsus angulatus. El músculo de la quela exhibió una actividad de Na+-K+ ATPasa marcadamente dependiente de la concentración de ATP, pH y temperatura del medio de reacción. La actividad fue máxima a 1 mM de ATP, 30-37ºC y a pH 7.4. La actividad de AP levamisol-sensible se caracterizó parcialmente a pH fisiológico (pH 7.4) y a pH 8.0. La I50 fue de 8.8 y 8.0 mM de levamisol a pH 7.4 y 8.0 respectivamente. A ambos pH la actividad de AP levamisol-sensible exhibió una cinética michaeliana (Km=3.451 y 6.606 mM de pNPP, respectivamente). Las actividades de AP levamisol-sensibles fueron fuertemente afectadas por la temperatura, exhibiendo un pico a 37ºC. En cangrejos aclimatados a baja salinidad (10) (condiciones de hiperregulación), las actividades de Na+-K+ ATPasa y de AP levamisol-sensible a pH fisiológico fueron mayores que a 35 de salinidad (condiciones de osmoionoconformación). La respuesta a baja salinidad sugiere que ambas actividades serían componentes de los mecanismos regulatorios a nivel bioquímico secundarios a la hiperregulación en C. angulatus. El estudio de estas actividades contribuye a un mejor conocimiento de los complejos mecanismos bioquímicos en el proceso adaptativo bajo condiciones de hiperregulación de cangrejos eurihalinos.The occurrence, characteristics and response to changes in environmental salinity of Na+-K+ ATPase and levamisole-sensitive alkaline phosphatase (AP) activities were studied in chela muscle of the euryhaline crab Cyrtograpsus angulatus. Chela muscle exhibited an Na+-K+ ATPase activity which was strongly dependent on ATP concentration, pH and temperature of the reaction mixture. Maximal activity was found at 1 mM ATP, 30-37ºC and pH 7.4. Levamisole-sensitive AP activity was characterised at physiological pH 7.4 and at pH 8.0. I50 for levamisole-sensitive AP activity was 8.8 mM and 8.0 mM at pH 7.4 and 8.0, respectively. At both pH levels, levamisole-sensitive AP activity exhibited Michaelis-Menten kinetics (Km=3.451 mM and 6.906 mM at pH 7.4 and 8.0, respectively). Levamisole-sensitive AP activities were strongly affected by temperature, exhibiting a peak at 37ºC. In crabs acclimated to low salinity (10; hyperegulating conditions), Na+- K+ ATPase activity and levamisole-sensitive AP activity at the physiological pH were higher than in 35 psu (osmoconforming conditions). The response to low salinity suggests that both activities could be components of muscle regulatory mechanisms at the biochemical level secondary to hyperegulation of C. angulatus. The study of these activities under hyperegulating conditions contributes to a better understanding of the complexity of biochemical mechanisms underlying the adaptive process of euryhaline crabs.Fil: Pinoni, Silvina Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Assessment of HSP70 and catalase in Brachidontes rodriguezii (d’Orbigny, 1842) a mussel from the Argentinean coast

Introduction: Intertidal ecosystems are complex environments of great importance for the ecological balance of coastal zones and are vulnerable areas to effects caused by natural stressors of global relevance such as temperature. Mussels, are often exposed to drastic variations of temperature and can show intracellular mechanisms of compensation that allow them to counteract exposure in the short and medium term at high temperatures. Heat shock proteins are chaperones that allow thermal stability of proteins against abrupt changes in temperature and catalase is an antioxidant enzyme thataid cells to fight against oxidative stress caused by diverse environmental stressors [1,2].Fil: Matos, Beatriz. Universidade Nova de Lisboa; PortugalFil: Pinoni, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Marcoval, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Diaz Jaramillo, Mauricio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Souza Diniz, Mario. Universidade Nova de Lisboa; Portuga

Osmotic and Ionic Regulation

The spatial and temporal changes in environmental salinity faced byintertidal estuarine crabs require a variety of strategies at different levels,for controlling movements of both water and ions between the organismsand their environment. The ability to osmoionoregulate is a primaryphysiological determinant for euryhalinity of these animals, and forinhabiting different zones within an intertidal area. Hyper- and hypoosmoionoregulationabilities allow maintenance of the osmotic and ionichemolymphatic concentrations within a stable range, either above or belowthat of the aquatic environment, this is, at low or high salinities,respectively (McNamara and Faria 2012). These abilities involve theactivation of their osmoionoregulatory machinery, from the molecularlevel to the entire organism. The gills of osmoregulating decapodcrustaceans are considered to be the main site of the biochemicaladaptations involved in ion transport processes (Lucu and Towle 2003,Larsen et al. 2014, for reviews). Euryhaline crabs compensate for theirpassive salt loss by active NaCl absorption across the epithelium of theposterior gills. So far, in most studied species, adaptive changes in gillNa+/K+ATPase activity and mRNA expression, have been clearly shownto occur and to be hormonally and non-hormonally regulated, being this enzyme one of the central molecular components of the ionoregulatoryprocess at the biochemical level (reviewed by Lucu and Towle 2003).Early studies, conducted on isolated perfused gills, suggest that NaClabsorption proceeds through basolateral Na+/K+-ATPase, and apicalNa+/H+andCl-/HCO3-exchangers (e.g. Siebers et al. 1985, Gilles andPéqueux 1986). Later studies with more refined techniques, expanded thelist of known ion transport proteins and proposed different mechanisticmodels for explaining ion absorption across the gill epithelium ofestuarine, euryhaline, freshwater crabs, and other decapod crustaceans(reviewed by e.g. Péqueux 1995, Henry et al. 2012, McNamara and Faria2012, Larsen et al. 2014).The biochemical adaptations in other organs or tissues of euryhalinecrabs to varying environmental conditions are scarcely known. Severalresponses have been shown to occur in muscles of crabs during osmoticadaptation (Whiteley et al. 2001, Pinoni and López Mañanes 2004, Larsenet al. 2014, Asaro et al. 2018a). On the other hand, adaptive compensationin response to different environmental conditions is an energy-demandingprocess which requires the mobilization of energy substrates formetabolically support osmoionic active transport (Wang et al. 2016,Pinoni et al. 2018).Neohelice granulata is a euryhaline crab considered an emergentanimal model for biochemical, physiological, and ecological research(Spivak 2010). This crab inhabits estuarine and oligohaline habitats and isfrequently found in rainwater pools or concentrated seawater pools. N.granulata has been identified as hyper-hypo-osmoionoregulator (MañéGarzón et al. 1974, Luquet et al. 1992, 1998, Schleich et al. 2001, Pinoniet al. 2013).In this chapter, we describe current knowledge about osmotic and ionicregulation at the biochemical and physiological levels, in adults of N.granulata. Aspects covered will include tolerance to salinity,osmoregulatory patterns, active transport, and functional morphology ofthe gills, as well as biochemical and metabolic responses in extrabranchialtissues to changes in environmental salinity.Fil: Luquet, Carlos Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Pinoni, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Alkaline phosphatase activity sensitive to environmental salinity and dopamine in muscle of the euryhaline crab Cyrtograpsus angulatus

The occurrence, characteristics and response to environmental salinity and dopamine of alkaline phosphatase (AP) activity were studied in chela muscle of the euryhaline crab Cyrtograpsus angulatus from Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina). Chela muscle exhibited a high AP activity with a Michaelis –Menten kinetic (Km=1.21 mM). AP activity was strongly inhibited by EDTA (I50=2.26 mM). AP activity appeared to be sensitive to environmental salinity. In crabs acclimated to low salinity (10x) AP activity was lower than in 35x salinity. Upon an abrupt change to reduced salinity a short-term decrease of AP activity occurred, concomitant with the transition to hyperregulation. Furthermore, AP activity appeared to be under hormonal control since it was inhibited ‘‘in vivo’’ by 10 4 M dopamine. The response to both environmental salinity and dopamine suggests that AP activity could be a component of muscle regulatory mechanisms at the biochemical level secondary to hyperregulation of C. angulatus. The possible functional relationship of AP activity with Na+ /K+ ATPase in muscle is discussed.Fil: Pinoni, Silvina Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentin

Flexibilidad digestiva en el cangrejo eurihalino Cyrtograptus angulatus (Decapoda, Brachyura, Varunidae) de la laguna costera de Mar Chiquita (Buenos Aires, Argentina): respuestas a la salinidad de enzimas clave en hepatopáncreas

En la laguna costera de Mar Chiquita (Argentina) Cyrtograptus angulatus es uno de los cangrejos dominantes con un importante papel ecológico. Sin embargo, faltan estudios sobre su fisiología y flexibilidad digestiva (ej. existencia y modulación de enzimas digestivas clave). En este estudio caracterizamos la actividad de fosfatasa alcalina (AP) en hepatopáncreas y estudiamos las respuestas post-ingesta a corto y largo plazo a baja salinidad ambiental (10 psu) de actividades de AP y proteolítica en hepatopáncreas. El hepatopáncreas exhibió actividades de AP insensible y sensible a levamisol con características bioquímicas diferentes. En cangrejos aclimatados a 10 psu (hiper-regulación), la actividad de AP levamisol-insensible disminuyó a largo plazo (48 h) post-ingesta, mientras que no se produjeron cambios en 35 psu (osmoconformación). No hubo cambios en la actividad de AP levamisol-sensible en ninguna de las salinidades estudiadas. En 35 psu, la actividad proteolítica se redujo a corto plazo postingesta (2- 4 h), mientras que no se encontraron cambios en 10 psu. Las diferentes respuestas post-ingesta de las actividades de AP levamisol-insensible y proteolítica en hepatopáncreas en 10 y 35 psu sugieren un papel de estas actividades en ajustes digestivos y metabólicosIn Mar Chiquita coastal lagoon (Argentina) Cyrtograpsus angulatus is one of thedominant intertidal euryhaline crabs having an important ecological role. However, studies ondigestive physiology and flexibility (i.e. occurrence and modulation of key digestive enzymes)are lacking. We determined the occurrence and characteristics of alkaline phosphatase (AP)activity in hepatopancreas and studied the responses to low salinity at short and long-term afterfeeding of AP and proteolytic activities in hepatopancreas. The hepatopancreas exhibited alevamisole-insensitive and a levamisole-sensitive AP activity with distinct biochemicalcharacteristics. In crabs acclimated to 10 psu (hyper-regulation conditions), levamisoleinsensitiveAP activity decreased at long term (48 h) after feeding, while no changes occurred incrabs acclimated to 35 psu (osmoconforming conditions). No changes occurred in levamisolesensitiveAP activity at any salinity tested. In 35 psu, proteolytic activity decreased at short termafter feeding (2- 4 h) while no changes were found in 10 psu. The different responses afterfeeding of levamisole-insensitive AP and proteolytic activities of hepatopancreas at 10 and 35psu, suggest a role of these activities in digestive and metabolic adjustments underlyingbiochemical adaptation to environmental salinity.Fil: Pinoni, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Na+ ATPase activities in chela muscle of the euryhaline crab Neohelice granulata: Differential response to environmental salinity

The occurrence and characteristics of ouabain-insensitive Na+ ATPase activity and the response to environmental salinity of the coexistent Na+-K+ ATPase and ouabain-insensitive Na+ ATPase activities were studied in chela muscle of the euryhaline crab Neohelice (Chasmagnathus) granulata from Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina). Chela muscle exhibited two ouabain-insensitive Na+ ATPase activities (a furosemide-insensitive and a furosemide-sensitive activity). I50 for ouabain-insensitive, furosemide-sensitive Na+ ATPase activity was about 1.4 mM. Both ouabain-insensitive, furosemide-insensitive and furosemide-sensitive Na+ ATPase activities were weakly affected by pH and showed Michaelis-Menten kinetics (Km = 0.021 and 0.224 mM, respectively). These characteristics appeared to be quite different from those previously described for Na+-K+ ATPase activity in chela muscle of this crab. Na+-K+ ATPase and ouabain-insensitive, furosemide-sensitive Na+ ATPase activities appeared to be sensitive to environmental salinity. In crabs acclimated to low salinity (10‰), a salinity at which N. granulata exhibits a strong hyperregulatory capacity, Na+-K+ ATPase activity was higher (117 ± 26 nmol Pi min- 1 mg prot- 1) than in 35‰ salinity (23 ± 6 nmol Pi min- 1 mg prot- 1) (a salinity at which this crab is osmoionoconforming). On the contrary, ouabain-insensitive, furosemide-sensitive Na+ ATPase activity was higher in 35‰ salinity (108 ±15 nmol Pi min- 1 mg prot- 1) than in crabs acclimated to 10‰ salinity (36 ± 11 nmol Pi min- 1 mg prot- 1). Ouabain-insensitive, furosemide-insensitive Na+ ATPase activity was not affected by acclimation of crabs to low salinity. The response to low salinity suggests that Na+-K+ ATPase could be a component of muscle regulatory mechanisms at the biochemical level secondary to hyperregulation whereas ouabain-insensitive, furosemide-sensitive activity appeared to be predominant upon osmoconforming conditions. The possible differential functional roles of Na+-K+ ATPase and ouabain-insensitive Na+ ATPase activities in muscle are discussed.Fil: Pinoni, Silvina Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentin

Feeding and osmoregulation in the euryhaline crab Neohelice granulata: Digestive parameter responses

When a species often experiences variation in its environmental conditions, metabolic flexibility is required. We studied the duration of the digestive cycle and the activity of key digestive enzymes (proteolytic, amylase, lipase) at short and long times after feeding in the hepatopancreas of the osmoregulator crab Neohelice granulata from the Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina). We compared these responses upon hyper-regulation and under osmoconformation conditions (10 and 35 psu). The results show the ability of this crab to hyper-regulate in different feeding states. No significant differences were observed in the duration pattern of the digestive cycle between hyper-regulation and osmoconformity. However, distinct responses after feeding were observed in the activities of the digestive enzymes studied in relation to the osmoregulatory state. In individuals exposed to 35 psu, proteolytic activity was higher at 8 h and remained constant until 72 h after feeding. At 10 psu, this activity was higher at 48 h after feeding than before feeding. At 35 psu, the amylase activity after feeding was greater than the prefeeding activity. No differences were observed in the activity of lipase at 35 psu, but at 10 psu this activity was lower 1 h after feeding than before feeding. This work constitutes a contribution to our knowledge of the physiology of crustaceans and attempts to clarify the possible mechanisms of digestive settings associated with hyper-regulation.Fil: Méndez, Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Pinoni, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Digestive flexibility in a euryhaline crab from a SW Atlantic coastal lagoon: Alkaline phosphatase activity sensitive to salinity in the hepatopancreas

We studied biochemical characteristics and the response to low salinity at short and long-term after feeding of alkaline phosphatase (AP) activity in hepatopancreas of the osmoregulator crab Neohelice granulata from Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina) (37°32′-37°45′S 57°19′-57°26′W). The hepatopancreas exhibited a levamisole-insensitive and a levamisole-sensitive AP activity with distinct characteristics. Levamisole-insensitive activity was similar within the range of pH 7.4-9.0 and exhibited a Michaelis-Menten kinetics. Levamisole-sensitive AP activity appeared to be maximal at pH 8.5 and appeared to exhibit an allosteric kinetics. In crabs acclimated to 10 psu (hyper-regulation conditions) levamisole-insensitive and levamisole-sensitive AP activity increased (about 16-fold) over time from short term (2-4 h) to long term (120 h) after feeding while no changes occurred in crabs acclimated to 35 psu (osmoconforming conditions). The changes of AP activity along with the higher values at 120 h after feeding in 10 psu compared with those in 35 psu, and the concomitant changes in proteolytic activity, suggest a role of AP in digestive and metabolic adjustments at the biochemical level upon hyper-regulatory conditions.Fil: Pinoni, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Méndez, Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Alkaline phosphatase activities in muscle of the euryhaline crab Chasmagnathus granulatus: Response to environmental salinity

The occurrence, characteristics and response to environmental salinity of alkaline phosphatase (AP) activity were studied in chela muscle of the euryhaline crab Chasmagnathus granulatus from Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina). Chela muscle exhibited a levamisole-insensitive and a levamisole-sensitive AP activities with distinct characteristics. Levamisole-insensitive activity appeared to be maximal at pH 7.7, whereas levamisole-sensitive AP activity was similar with the range of pH 7.4 to 8.0. Both activities at pH 7.7 exhibited a Michaelis-Menten kinetics (Km = 0.789 and 1.416 mM, respectively). I50 for levamisole-sensitive AP activity was about 12 mM. Levamisole-insensitive and levamisole-sensitive AP activities were differentially affected by temperature. Levamisole-sensitive AP activity was quite sensitive to temperature, exhibiting a peak at 37°C but being low at 5 to 30°C and 45 to 60°C. Both activities were inhibited by Cu2+. At 1.0 mM Cu2+, levamisole-insensitive AP activity was inhibited about 82% whereas levamisole-sensitive AP activity was almost completely inhibited. Levamisole-insensitive AP activity appeared to be sensitive to environmental salinity. In crabs acclimated to low salinity (10‰) this activity was lower than in 35‰ salinity. The response to environmental salinity suggests that levamisole-insensitive AP activity could be a component of muscle regulatory mechanisms at the biochemical level secondary to hyperregulation of C. granulatus. The possible physiological roles and functional relationship of AP activity with Na+/K+ ATPase in muscle are discussed.Fil: Pinoni, Silvina Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Goldemberg, Adriana Lia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentin

Between-habitat comparison of digestive enzymes activities and energy reserves in the SW Atlantic euryhaline burrowing crab Neohelice granulata

The digestive and metabolic characteristics at the biochemical level underlying between-habitat dietary shift of the SW Atlantic euryhaline burrowing crab Neohelice granulata under natural conditions are unknown. We made studies on adult males of N. granulata from the open mudflat and the vegetated saltmarsh in a SW Atlantic costal lagoon (Mar Chiquita, 37°32′–37°45′S; 57°19′–57°26′W, Argentina). We determined and compared amylase, maltase, sucrase, proteolytic, lipase and alkaline phosphatases activities in the hepatopancreas; glycemia, and glycogen, free glucose, triglycerides and protein concentrations in hepatopancreas, chela muscle, and anterior and posterior gills. The results show that N. granulata exhibits characteristics and between-habitat differences at the biochemical level (i.e. high amylase and disaccharidaseactivities, differences in total proteolytic, lipase and levamisole-insensitive AP activities in the hepatopancreas, and in the concentrations of glycogen in the gills, triglycerides in the hepatopancreas and of protein in the chela muscle) which could represent adaptive digestive and metabolic strategies to face the differences in environmental conditions (i.e. food availability). The possible relationship between digestive and metabolic characteristics and feeding patterns, type of food available and environmental conditions in each habitat is discussed.Fil: Pinoni, Silvina Andrea. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Iribarne, Oscar Osvaldo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Lopez Mañanes, Alejandra Antonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentin